Currently, there are many kinds of actuator designs which use pressure or torque to force the rotation of the shaft in the actuator (in both clockwise and counterclockwise manners) to drive the rotary valve to open and close, and further control the on/off position of the valve in a pipeline. There are two types of pneumatic rotary actuators: single-acting and double-acting. The single-acting actuator is used on the valve that requires fail-return and traditional single-acting actuators typically rely on the compression or torsion of springs. The released force in the spring provides resilient force for the fail-return action (either fail-open or fail-close) and when there is supply of pressurized air, the spring tension must first be overcome to drive the shaft to open or close the valve, so the effective torque will decrease as the spring resistance increases. When there is no supply of pressurized air, the actuator can use returning force of the spring to rotate the shaft and valve to its fail-return position (either fail-open or fail-close). The operation is so called “fail-return,” and the output torque will decrease as tension in the spring diminishes. As to the double-acting actuator operation, generally the supply of pressurized air source is necessary and the supply of the pressurized air, which is in and out of the actuator, drives the shaft and valve to open or close. When there is no supply of pressurized air, the actuator cannot move, unlike the single-acting actuators which can rely on the spring tension as the fail-return force to fail-open or fail-close the valve. However, when there is supply for pressurized air, the open and close torque output will be far higher than that of the single-acting actuators. Traditionally the single-acting actuators and double-acting actuators require a solenoid air flow control valve in combination with gas and electricity, to open or close the valve. In the event there is no supply of pressurized air and/or electricity and there is an emergency need to open or close the valve, the traditional method is to install a declutchable manual gear operator (gear box) underneath the actuator to act as an emergency switch when there is no air source. But the disadvantage is the packaging occupies more spaces and the total cost is higher. In addition, from the manufacturing and distributor's perspective, they must produce and inventory the single-acting and double-acting actuators in response to the different needs from customers. If they cannot provide a single product that can perform both single-acting and double-acting functions, the total production and inventory costs will increase accordingly.